In recent years, to detect a point for improvement in a machine tool such as a milling machine, it has been requested to monitor the state of the blade portion of a cutting tool during cutting in real time. As a technique which detects the machining state of a machine tool, e.g., Patent Literature 1 is known. Patent Literature 1 discloses a technique which attaches a thermocouple to the cutting edge of a machine tool to detect the temperature of the cutting edge and detects the machining state of the machine tool on the basis of the detected temperature. Specifically, in Patent Literature 1, the machining state is determined using a correlationship such that a change in the temperature of the cutting edge is proportional to the amount of cutting (cutting depth).
On the other hand, in Patent Literature 2, it is disclosed that a sensor such as a vibration sensor, a rotation sensor, or a temperature sensor is attached to a wireless sensor, the identification information of the sensor is added to detection information resulting from detection by the sensor, the detection information is transmitted to a management device using radio waves, and the management device categorizes the detection information on the basis of the identification information and stores the detection information. Here, in Patent Literature 2, in the case where the sensor is attached to a rotation shaft mounted in a working machine, a vehicle, or the like, when the sensor and the management device are connected with a communication line, the communication line is broken so that the detection information is wirelessly transmitted to the management device.
However, in Patent Literature 1, a tool bit is assumed as the cutting tool and a cutting tool configured of a rotating body as assumed in the present application is not assumed. Also, in Patent Literature 1, only the temperature of the cutting edge is assumed to be a measurement target. This presents a problem in that a change in the state of the cutting edge can be measured only with a macro resolving power of the order of seconds and high-resolution measurement cannot be performed.
Also, in Patent Literature 2, the detection information resulting from the detection by the sensor is wirelessly transmitted to the management device. However, the management device only categorizes the detection information on the basis of the identification information and stores the detection information and does not display the detection information in real time on a display section.